CCSD3ZF0000100000001NJPL3IF0PDSX00000001 PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM SPACECRAFT_NAME = "INFRARED ASTRONOMICAL SATELLITE" INSTRUMENT_NAME = "FOCAL PLANE ARRAY" INSTRUMENT_ID = FPA OBJECT = TEXT NOTE = "Introduction to this CD-ROM volume." PUBLICATION_DATE = 1994-07-22 END_OBJECT = TEXT END 1. Introduction This CD-ROM volume(#1) contains the data stream output of the Infrared Astronomical Satellite (IRAS) as organized in the Low and Medium-Resolution Zodiacal History Files. All data was generated by the Infrared Processing and Analysis Center (IPAC) at the California Institute of Technology. They were organized along with the supporting calibration and index files by the Dust Subnode of the Small Bodies Discipline Node of the NASA Planetary Data System for distribution to the general community. IRAS conducted three surveys of the sky in four broad passbands centered at 12, 25, 60, and 100 microns. The principal instrument was a focal plane array of 62 detectors, divided into eight parallel modules, two for each color band. Each module contains either seven or eight detectors. As the satellite orbited the Earth the array swept out a path 0.5 degrees in width. The parallel modules allowed for discrimination between astrophysical sources (stars, asteroids) and spurious signals due to cosmic ray strikes and Earth orbiting debris. A complete description of IRAS and the focal plane array is found in the IRAS Explanatory Supplement (Beichman et al., 1988, JPL RP-1190). 2. Disk Format The disk has been formatted so that a variety of computer systems (e.g. IBM PC, Macintosh, Sun, VAX) may access the data. Specifically, the disk is formatted according to the ISO 9660 level 1 Interchange Standard. The disk will appear to the user to be identical to a file system of directories, sub-directories, and data files. 3. File Format PDS label formats and documentation conform to standards as defined by the Planetary Data System Standards Reference (JPL D-7669, Part 2, November 1992, Version 3.0) and the Planetary Science Data Dictionary (JPL D-7116, November 1992, Rev. C). 4. Directory and File Information The file structure of this disk is as follows: /AAREADME.TXT - This file, which you are currently reading, contains general information about the format of this disk. /VOLDESC.CAT - This file contains information about the datasets that reside on this disk. /CALIB/ - This directory contains information that is pertinent to the detector response and filter transmissions. See /CALIB/CALINFO.TXT for information about the files in /CALIB. /CATALOG/ - This directory contains the templates that refer to the datasets. See /CATALOG/CATINFO.TXT for information about the files in /CATALOG. /INDEX/ - This directory contains the scan history information and the binary file indices. See /INDEX/INDXINFO.TXT for information about the files in /INDEX. /ZOHF1/ - This directory contains the low resolution data. /ZOHF2/ - This directory contains part of the medium resolution data. 5. Volume Set Structure This is the first CD-ROM of the Infrared Astronomical Satellite Observations volume set. Due to the size of the datasets contained on the CD-ROM's, four volumes were created. The first three volumes contain the low and medium resolution zodiacal history files datasets in ASCII format, and the fourth volume contains binary forms of these datasets. To assist in finding information contained in this volume set, the following briefly describes the structure of the CD-ROM's in this volume set. Each CD-ROM has the following identical files: CALIB/CALINFO.TXT - see this file for information about the CALIB directory CALIB/FILTER1.TAB CALIB/FILTER1.LBL CALIB/FILTER2.TAB CALIB/FILTER2.LBL CALIB/FILTER3.TAB CALIB/FILTER3.LBL CALIB/FILTER4.TAB CALIB/FILTER4.LBL CATALOG/CATINFO.TXT - see this file for information about the CATALOG directory CATALOG/FLTRS_DS.CAT CATALOG/INST.CAT CATALOG/INSTHOST.CAT CATALOG/MISSION.CAT CATALOG/REF.CAT CATALOG/SCAN_DS.CAT CATALOG/ZOHF1_DS.CAT CATALOG/ZOHF2_DS.CAT INDEX/INDXINFO.TXT - see this file for information about the INDEX directory INDEX/SCAN.TAB INDEX/SCAN.LBL INDEX/ZOHF_LOW.LBL INDEX/ZOHF_LOW.TAB INDEX/ZOHF_MED.LBL INDEX/ZOHF_MED.TAB In addition to these files, each CD-ROM will contain the following: AAREADME.TXT - Description of each disk (You are currently reading the one for CD-ROM 1). VOLDESC.TXT - Description of the datasets contained on the disk. Unique to each CD-ROM will be: CD-ROM 1 - The IRAS Low Resolution Dataset (5749 tables) and part of the Medium Resolution Dataset (SOPs 29 - 179)(1448 tables). CD-ROM 2 - Part of the IRAS Medium Resolution Dataset (SOPs 180 - 399) (2225 tables). CD-ROM 3 - Part of the IRAS Medium Resolution Dataset (SOPs 400 - 600) (2076 tables). CD-ROM 4 - Binary forms of the IRAS Low and Medium Datasets (2 data files). 6. Cognizant Persons Catalog table and label files and CD-ROM Documentation were generated at the University of Arizona by Mark Sykes, Shane Jensen, Kevin Garlow, and Elizabeth Alvarez del Castillo. Calibration files were generated by IPAC. Index files were generated by Mark Sykes.